The present invention relates to a laser micro-dissection system for the processing of a biological or non-biological mass, in particular a laser micro-dissection system for the processing, separation, and/or obtaining of microscopically small biological and/or non-biological objects of a biological or non-biological mass.
A conventional laser micro-dissection system of this kind from the Applicants is known from WO 97/29355 A or WO 01/73398 A. With the laser micro-dissection system described in these printed specifications, individual biological or non-biological objects, which are arranged on a planar carrier, can be selected with the assistance of a computer and processed with a laser beam. In this situation, a selected object can be separated from the surrounding mass, for example with the aid of a laser beam and with the assistance of a computer, in order for the selected object to be prepared free of the surrounding mass. The freely prepared object can then be catapulted by means of a laser-induced conveying process with the aid of a laser shot, which is directed onto the freely-prepared object, from the carrier to a catchment device. As a carrier, use can be made, for example, of a polymer film.
The method described previously allows for the separation, sorting, and obtaining of both biological as well as non-biological objects. Within the scope of the present patent application the term “biological objects” is understood to mean in particular living or fixed biological cells or cell constituents, which are constituent parts of a fluid or solid biological material, such as a piece of cell tissue, a smear, or a cell culture, etc. With the aid of the method described previously, the objects selected in each case are loaded specifically with a selected substance by means of contact-free laser microinjection, and the successfully injected biological objects are then sorted out. The biological objects may be located next to one another on a fixed planar carrier, whereby the process of separation can be carried out within a short time and free of contact. The survival capability and morphology of the biological objects is ensured; i.e. the biological objects are not damaged or impaired by the micro-injection procedure and by the separation and catapulting process.
In principle, the laser-induced conveying process explained previously, i.e. the catapulting out of objects previously selected individually from the surrounding mass in each case, can be carried out even without previous free preparation of the object selected in each case, if the laser energy and/or the laser focus at the moment of setting the separate laser shot is or are selected in such a way that the resulting impulse force of this laser shot is sufficient for releasing the corresponding object from the surrounding mass and for the conveying process to the catchment device.
Because the method described previously can be carried out manually with the desired degree of precision only with a relatively high degree of effort, the laser micro-dissection systems from the patent specifications referred to previously are designed to be computer-assisted, i.e. the cutting out and/or catapulting of a selected object is carried out with computer assistance, so that the laser light source which generates the laser beam which serves for the cutting and/or catapulting is actuated automatically, and the relative movement between the laser beam and the carrier with the biological or non-biological objects, required for the cutting and/or catapulting, is automatically induced and controlled. In particular, a computer-assisted selection or marking of the desired objects located on the carrier is possible, so that these can subsequently be processed automatically with the laser micro-dissection system. For this purpose the laser micro-dissection system comprises a display screen or monitor, on which a video image of the material located on the carrier, recorded by a digital camera, is displayed. The user can draw on the display screen or the video image, for example with the aid of appropriate graphic tools, a desired cutting curve, which is then followed automatically by the laser beam with computer assistance, in order to cut out the object selected in this way. In a similar manner, a desired object can also be marked on the display screen or video image in order for it to be catapulted out, whereby the separate laser pulse or laser shot is then imposed at the desired location.
Although with the known laser micro-dissection systems explained previously computer-assisted and automated processing of the material situated on the carrier is in principle already provided, nevertheless the processing of a number of biological objects, which in particular may be of different kinds, is relatively elaborate, since the objects may either be processed individually or in their entirety.